The present disclosure relates to the field of agricultural implements drawn by motive power sources such as tractors and used for planting. More particularly, the present disclosure relates to a paddle sealer having closing wheels for closing seed trenches in a manner to promote uniform germination and emergence.
In damp soil conditions, conventional closing wheels commonly found on seeding equipment can compact the soil used to close the seed trench. This can result in undesirable effects. Excessive soil compaction impedes root growth and therefore limits the amount of soil explored by roots. This, in turn, can decrease the plant's ability to take up nutrients and water. From the standpoint of crop production, the adverse effect of soil compaction on water flow and storage may be more serious than the direct effect of soil compaction on root growth.
In dry years, soil compaction can lead to stunted, drought stressed plants due to decreased root growth. Without timely rains and well-placed fertilizers, yield reductions will occur. Soil compaction in wet years decreases soil aeration. This results in increased denitrification (loss of nitrate-nitrogen to the atmosphere). There can also be a soil compaction induced nitrogen and potassium deficiency. Plants need to spend energy to take up potassium. Reduced soil aeration affects root metabolism. There can also be increased risk of crop disease. All of these factors result in added stress to the crop and, ultimately, yield loss.
In the farming practice of strip till, a berm of soil is created by a specially designed fertilizer knife injecting soil additive and a pair of angled sealing discs. The most common used soil additive is anhydrous ammonia (NH3), a nitrogen fertilizer. NH3 rapidly turns from a liquid state to a gas during the application process and must be sealed before it reaches the soil surface. The conventional method used to seal NH3 is by relocating soil on top of the berm using a pair of concave sealing discs. This method does not adequately seal in the NH3 and escape of the NH3 occurs. In addition, soil clods are commonly relocated to the top of the berm. The drawback to this method is that an inconsistent berm height is created by the clods, which traps air and impedes settling of the soil in the berm. Strip till is normally practiced in the fall, giving the soil time to settle before seeds are planted into the berm the following spring. Any trapped air in the berm during planting can impact seed germination, as well as seed depth. If soil settling occurs after planting, the depth of the seeds will vary, which could have a negative effect on emergence.